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4. 0 FINDINGS ' 4. 1 Stratigraphy The upper 30 feet of soil in MW-3 and MW-4 consist of brown, ' slightly oxidized clayey to sandy silt or silty sand. This unit appears to coarsen downward slightly. Oxidized, red-brown clayey silt is present at 35 feet. Gray-brown to brown silty clay and clayey silt are characteristic of most samples from 35 to 70 feet. ' Below this depth, silty clay, clayey silt, and silty, fine-grained sand are interbedded. Poorly sorted sand was encountered at 100 feet in MW-3 . Samples below 80 feet were moist, and samples below ' 95 feet were saturated. The boring logs are included in Appendix A. 4 .2 Soil Contamination ' No TPH or BTE&X contamination was detected in any of the soil samples that were analyzed. Bromomethane (HVOC) was detected in sample MW4-45 at 0 . 43 µg/g (ppm) . No other HVOC's were detected in ' any of the samples analyzed. The laboratory report and chain-of- custody are included in Appendix B. 4. 3 Groundwater Gradient and Direction Monitoring well survey and groundwater depth data are summarized in Table 2 . At the time of monitoring, groundwater depth at the site ' was approximately 86 feet. The depth to groundwater has dropped about 2 . 5 feet since the March monitoring and follows the pattern of falling water levels seen elsewhere in the county in the fall. The present gradient is 0. 0009 ft/ft, oriented N 140 E (Figure 3) . This is a very flat gradient, which implies very slow groundwater flow. It also implies that very slight changes in water levels can effect ma3or shifts in groundwater gradient and flow direction. At present, MW-3 is directly down-gradient from the former UST cavity. TABLE 2 RELATIVE GROUNDWATER ELEVATIONS October 4, 1993 Relative Relative Well No. Casing Depth to Groundwater Elevation Groundwater Elevation MW-2 98. 91 85.98 12 . 93 MW-3 99. 37 86.51 12 . 86 MW-4 99 . 11 86.21 12 . 90 * Measurements in feet I 7